Billy Melchionni (born October 19 1944 in Philadelphia, Pennsylvania) is a former NBA and ABA player. Melchionni was a wispy guard from Bishop Eustace Prep (Camden, NJ) who was a collegiate star in the 1960's at Villanova University. Upon graduation from Villanova, Melchionni joined the famous Phillips 66ers AAU Elite team, where he starred for a season before returning to his hometown to join the Philadelphia 76ers. Melchionni was a key reserve on the greatest of the 76ers teams, NBA Champions led by Wilt Chamberlain, Luke Jackson, Hal Greer, Wally Jones, and Chet Walker in 1967. The team was coached by another AAU Elite alum, Alex Hannum. Melchionni then jumped to the upsart ABA, becoming a key cog with the New York Nets, mentoring a young Julius Erving. Here Melchionni was a key player in an ABA Championship, led by Dr J, Larry Kenon, Fred Williamson, and Billy Paultz.

The Nets retired Melchionni's #25 jersey.